JP2021145521A - Electric power conversion device - Google Patents

Abstract

To provide an electric power conversion device which can secure strength of a circuit board even in a shield structure.SOLUTION: An electric power conversion device includes: a base member 30 in which a shield wall 31 stands so as to partition a component 100 of a high voltage input noise filter; a cover member which closes an opening of the base member 30; and a circuit board 50 disposed between an end part 37 of the shield wall 31 and the cover member. The circuit board 50 has through holes 70, 80 along the shield wall 31.SELECTED DRAWING: Figure 3

Description

The present invention relates to a power converter.

In the power conversion device disclosed in Patent Document 1, a case in which the entire bottom surface and side surfaces are formed of a metal material and the upper surface is open, and a cover member formed of a metal material covering the upper surface of the case are provided, and the power conversion device is provided from the bottom surface of the case. A shielding wall is erected in the vertical direction to form a first accommodating portion and a second accommodating portion separated by the shielding wall. The input filter circuit section is housed in the first housing section, the power system main circuit section, control circuit section, and output filter circuit section are housed in the second housing section, and the cover member is in contact with the shielding wall. ing. Separates the multilayer printed circuit board that electrically connects the components that make up the input filter circuit and the multilayer printed circuit board that electrically connects the components that make up the power system main circuit, control circuit, and output filter circuit. doing. Electrical noise is shielded by dividing the board and installing a wall inside the housing.

JP-A-2019-75917

Here, in order to omit the connection structure between the boards, let's arrange the parts that make up the input filter circuit part and the parts that make up the power system main circuit part, the control circuit part, and the output filter circuit part on one board. Then, it is necessary to make a notch in the board so as to avoid the shielding wall so that the shielding wall can pass through the notch. Is easy to join.

An object of the present invention is to provide a power conversion device capable of ensuring the strength of a circuit board even with a shielding structure.

The power conversion device for solving the above problems is a power conversion device including a switching element, which comprises a base member on which a shielding wall is erected, a cover member that closes an opening of the base member, and the shielding wall. A circuit board arranged between an end portion and the cover member is provided, and the circuit board has a plurality of through holes along the shielding wall.

According to this, the circuit board is arranged between the shielding wall and the cover member, and noise can be shielded by a plurality of through holes along the shielding wall. Therefore, since the circuit board is not formed with a notch, the circuit board is less likely to bend, and the stress of the solder and the board-mounted components formed on the circuit board due to the bending can be suppressed. As a result, the strength of the circuit board can be ensured even with the shielding structure.

Further, in the power conversion device, it is preferable that the through hole is connected to the ground pattern of the circuit board.
Further, in the power conversion device, it is preferable that solder is formed on at least one of the base member side and the cover member side corresponding to the shielding wall of the circuit board.

Further, in the power conversion device, it is preferable that the solder is in contact with the end portion of the shielding wall or the cover member.
Further, in the power conversion device, it is preferable that the solder is connected to the ground pattern of the circuit board.

According to the present invention, the strength of the circuit board can be ensured even with the shielding structure.

An exploded perspective view of the power conversion device according to the embodiment. (A) is a partial plan view of the power conversion device, and (b) is a vertical cross-sectional view taken along the line AA of (a). A partial plan view of the power conversion device with the cover member removed, (b) is a vertical cross-sectional view taken along the line AA of (a). (A) is a partial plan view of the power conversion device with the cover member and the circuit board removed, and (b) is a vertical cross-sectional view taken along the line AA of (a). (A) is a partial plan view of the circuit board, and (b) is a vertical cross-sectional view taken along the line AA of (a). Partial plan view of the circuit board. FIG. 6 is a vertical cross-sectional view taken along the line AA of FIG. FIG. 6 is a vertical cross-sectional view taken along the line BB of FIG. A circuit diagram showing an electrical configuration of a power converter.

Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings.
As shown in FIG. 9, the power conversion device 10 including a switching element inputs a high voltage DC voltage from an input terminal and outputs an AC voltage from an output terminal. For example, an in-vehicle device that inputs a high voltage DC voltage from an in-vehicle power storage device and outputs it as an alternating current of 100 V can be mentioned.

The power conversion device 10 sequentially includes a high-voltage input noise filter 11 as an input filter circuit, a booster circuit 12, a DC / DC circuit 13, a DC / AC circuit 14, and an AC output from the input terminal side to the output terminal side. It has a noise filter 15.

The high-voltage input noise filter 11 includes a choke coil Lch, a pair of capacitors C1 and C2 connected in series on the input side of the choke coil Lch, and a pair of capacitors C3 and C4 connected in series on the output side of the choke coil Lch. It is composed of a pair of capacitors C3 and C4 and a capacitor C5 connected in parallel.

The booster circuit 12 includes a coil L1, a switching transistor Q1, and a diode D1.
The DC / DC circuit 13 includes a transformer Tr, a pair of capacitors C6 and C7 connected in series on the primary side of the transformer Tr, a pair of switching diodes Q2 and Q3 connected in series on the primary side of the transformer Tr, and a transformer. A pair of diodes D2 and D3 connected in series on the secondary side of the Tr, a pair of diodes D4 and D5 connected in series on the secondary side of the transformer Tr, and a capacitor C8 connected in series on the secondary side of the transformer Tr. It is composed of.

The DC / AC circuit 14 is composed of a resistor R1, a pair of switching transistors Q4 and Q5 connected in series, and a pair of switching transistors Q6 and Q7 connected in series.

The AC output noise filter 15 is composed of a coil L2, a coil L3, a capacitor C9, and a pair of capacitors C10 and C11 connected in series.
The specific configuration of the power conversion device 10 will be described with reference to FIGS. 1 to 8.

In the drawings, the horizontal plane is defined in the orthogonal X and Y directions, and the vertical direction is defined in the Z direction.
As shown in FIGS. 1, 2 (a) and 2 (b), the power conversion device 10 has a body-grounded housing 20, and the power conversion device 10 shown in FIG. 9 is contained in the housing 20. The various parts and the circuit board 50 constituting the above are housed. The housing 20 is composed of a square box-shaped base member 30 having an opening on the upper surface and a square plate-shaped cover member 40 that closes the opening of the base member 30. The cover member 40 is screwed to the base member 30. The base member 30 is made of aluminum and the cover member 40 is made of iron. The cover member 40 and the base member 30 are electrically connected by screw fastening.

The square box-shaped base member 30 has a bottom surface portion 30a, a pair of side surface portions 30b and 30c facing each other, and a pair of side surface portions 30d and 30e facing each other. The input connector 60 and the output connector 61 are arranged on the side surface portion 30b so as to be separated from each other in the Y direction. The input connector 60 is provided at a position close to the side surface portion 30d on the side surface portion 30b. The input connector 60 is fixed so as to penetrate the side surface portion 30b. The output connector 61 is provided at a position close to the side surface portion 30e on the side surface portion 30b. The output connector 61 is fixed so as to penetrate the side surface portion 30b.

As shown in FIGS. 4A and 4B, the component 100 of the high-voltage input noise filter 11 is arranged at the corner portion formed by the side surface portion 30b and the side surface portion 30d inside the housing 20. .. That is, the choke coil Lch and the capacitors C1, C2, C3, C4, and C5 in FIG. 9 are arranged.

A shielding wall 31 is erected on the base member 30 inside the housing 20 so as to partition the component 100 of the high-pressure input noise filter 11 as an input filter circuit. As shown in FIG. 4B, the shielding wall 31 extends in the Z direction from the bottom surface of the base member 30 toward the cover member 40. As shown in FIG. 4A, the shielding wall 31 has a parallel portion 31a and an oblique portion 31b. The parallel portion 31a extends in the X direction in parallel with the side surface portion 30d. The oblique portion 31b extends from the side of the parallel portion 31a that approaches the side surface portion 30b, extends obliquely in a direction away from the side surface portion 30d, and connects to the side surface portion 30b. A screw hole 36 is formed at the end of the parallel portion 31a. A screw hole 35 is formed at a boundary portion between the parallel portion 31a and the oblique portion 31b. A screw hole 34 is formed on the side surface portion 30b side of the oblique portion 31b.

As shown in FIGS. 2 (a), 2 (b), 3 (a), and 3 (b), the circuit board 50 is the end portion 37 of the shielding wall 31 in the housing 20 (base member 30). It is arranged between the cover member 40 and the cover member 40.

The circuit board 50 is screwed onto the base member 30. Specifically, as shown in FIGS. 4A and 4B, screw holes 32 and 33 are formed in the side surface portion 30d of the base member 30. Further, as shown in FIGS. 5A and 5B, through holes 51, 52, 53, 54, 55 are formed in the circuit board 50. Then, as shown in FIGS. 1, 3 (a), and 3 (b), the screw Sc1 is screwed into the screw hole 32 through the through hole 51. The screw Sc2 is screwed into the screw hole 33 through the through hole 52. The screw Sc3 is screwed into the screw hole 34 through the through hole 53. The screw Sc4 is screwed into the screw hole 35 through the through hole 54. The screw Sc5 is screwed into the screw hole 36 through the through hole 55. By forming screw holes 34, 35, 36 at the end 37 of the shielding wall 31 and screwing the circuit board 50, the solder (solder thread) 90 is surely attached to the end 37 of the shielding wall 31 as described later. Can be contacted with. Although not shown, the base member 30 and the circuit board 50 are screwed to the boss provided on the base member even at different parts. Then, the cover member 40 is screwed from above with screws (not shown).

As shown in FIGS. 5 (a), 5 (b), 6 and 8, the circuit board 50 has a plurality of through holes 70 and a plurality of through holes 80 along the shielding wall 31. The through holes 70 and 80 are plated through holes in which a conductor is formed by copper plating in a hole penetrating the circuit board 50.

The plurality of through holes 70 are formed along the shielding wall 31 at a position separated from the shielding wall 31 on one side from the arrangement location of the shielding wall 31 in a plan view (see FIG. 3A). The plurality of through holes 80 are formed along the shielding wall 31 at a position separated from the shielding wall 31 on the other side from the arrangement location of the shielding wall 31 in a plan view.

As shown in FIGS. 6 and 8, the through hole 70 is connected to the ground pattern 110 of the circuit board 50. The through hole 80 is connected to the ground pattern 111 of the circuit board 50.

As shown in FIGS. 5 (a), 5 (b), 6 and 7, a dummy solder (solder thread) 90 is provided on the base member 30 side at a position corresponding to the shielding wall 31 on the circuit board 50. It is formed intermittently. Further, a dummy solder (solder thread) 91 is intermittently formed on the cover member 40 side at a position corresponding to the shielding wall 31 on the circuit board 50. Explaining with reference to FIG. 3A, the solder (solder thread) 90 and the solder (solder thread) 91 are arranged so as to overlap the shielding wall 31 in a plan view. As described above, the solder (solder thread) 90 is formed on the base member 30 side corresponding to the shielding wall 31 of the circuit board 50, and the solder (solder thread) 91 is formed on the cover member 40 side. The reason why the solder (solder thread) 90 and the solder (solder thread) 91 are formed intermittently is that it becomes difficult to keep the height constant in the longitudinal direction (extending direction) if the solder (solder thread) 90 and the solder (solder thread) 91 are continuously extended.

It is sufficient that the solders (solder ridges) 90 and 91 are formed on at least one of the base member 30 side and the cover member 40 side of the circuit board 50.
As shown in FIG. 8, the solder (solder thread) 90 is in contact with the end portion 37 of the shielding wall 31. The solder (solder thread) 91 is in contact with the cover member 40.

The solder (solder ridges) 90, 91 may be in contact with the end portion 37 of the shielding wall 31 or the cover member 40, and the solder (solder ridges) 90, 91 may be in contact with the circuit board 50. It may be connected to the ground pattern 110.

In this way, the through holes 70 and 80 and the solder (solder threads) 90 and 91 have the same potential and the ground potential because they are connected to the ground patterns (conductor patterns) 110 and 111.

Next, the action will be described.
Noise is generated inside the housing 20 due to the switching operation of the switching transistor Q1 of the booster circuit 12. In addition, noise is generated due to the switching operation of the switching transistors Q2 and Q3 of the DC / DC circuit 13. Further, noise is generated due to the switching operation of the switching transistors Q4, Q5, Q6, and Q7 of the DC / AC circuit 14.

The generated noise is shielded from the high-voltage input noise filter 11 because the shielding wall 31 is formed around the component 100 of the high-voltage input noise filter 11. Further, since the circuit board 50 has a plurality of through holes 70 and a plurality of through holes 80 along the shielding wall 31, noise is shielded from the high voltage input noise filter 11. Further, since the solders (solder ridges) 90 and 91 are formed on the base member 30 side and the cover member 40 side corresponding to the shielding wall 31 of the circuit board 50, noise is shielded from the high voltage input noise filter 11. ..

In this way, in order to form a noise shielding structure using a single substrate, an integrated substrate having an enhanced electrical noise shielding ability, that is, a structure that does not block the electrical path can be formed. That is, by using a single substrate, it is possible to prevent the electrical path from being blocked.

Further, by installing the solders (solder threads) 90 and 91, the gap between the circuit board 50 and the shielding wall 31 and the gap between the circuit board 50 and the cover member 40 can be reduced, and the noise shielding ability can be enhanced.

Further, through holes 70 and 80 can be installed to enhance the noise shielding ability in the circuit board 50.
According to the above embodiment, the following effects can be obtained.

(1) As a configuration of a power conversion device 10 including switching transistors Q1 to Q7 as switching elements, a base in which a shielding wall 31 is erected so as to partition a component 100 of a high-voltage input noise filter 11 as an input filter circuit. The member 30, the cover member 40 that closes the opening of the base member 30, and the circuit board 50 arranged between the end portion 37 of the shielding wall 31 and the cover member 40 are provided, and the circuit board 50 is a shielding wall. It has a plurality of through holes 70, 80 along 31. According to this, the circuit board 50 is arranged between the shielding wall 31 and the cover member 40, and noise can be shielded by a plurality of through holes 70 and 80 along the shielding wall 31. Therefore, since the circuit board 50 is not formed with a notch, the circuit board 50 is less likely to bend, and the stress of the solder and the board-mounted components formed on the circuit board 50 due to the bending can be suppressed. As a result, the strength of the circuit board 50 can be ensured even with the shielding structure.

(2) Since the through holes 70 and 80 are connected to the ground patterns 110 and 111 of the circuit board 50, noise can be further shielded.
(3) Since solder (solder ridges) 90 and 91 are formed on at least one of the base member 30 side and the cover member 40 side corresponding to the shielding wall 31 of the circuit board 50, noise can be further shielded. ..

(4) Since the solders (solder threads) 90 and 91 are in contact with the end portion 37 of the shielding wall 31 or the cover member 40, noise can be further shielded.
(5) When the solders (solder threads) 90 and 91 are connected to the ground pattern 110 of the circuit board 50, noise can be further shielded.

(6) Through holes 70, 80 and solder (solder threads) 90, 91 can be formed by a normal circuit board manufacturing process. Therefore, no additional steps are required.
The embodiment is not limited to the above, and may be embodied as follows, for example.

○ Although dummy solders (solder threads) 90 and 91 are mounted on the circuit board 50, dummy conductor components (copper locks, etc.) may be surface-mounted instead.
○ The plurality of through holes 70 and the plurality of through holes 80 are formed along the shielding wall 31 at positions separated from the arrangement location of the shielding wall 31 in the plan view, but the plurality of through holes 70 and 80 are formed in the plan view. It may be formed along the shielding wall 31 at the place where the shielding wall 31 is arranged.

〇 The ground patterns 110 and 111 do not have to be formed so as to connect the through holes 70 and 80, respectively, as shown in FIG. It may be formed in a pattern wider than the end portion 37 of the shielding wall 31 so as to connect all the through holes 70, 80 and the solder 90, 91.

〇 Through holes 70, 80 and solder 90, 91 may not be formed over the entire length of the end portion 37 of the shielding wall 31, as long as they are partially formed.
〇 Either one of the through hole 70 and the through hole 80 may be used.

○ The power conversion device 10 is not limited to one that inputs direct current and outputs alternating current, and may be another power conversion device, for example, a DC / DC converter.

10 ... Power converter, 30 ... Base member, 31 ... Shielding wall, 37 ... End, 40 ... Cover member, 50 ... Circuit board, 70, 80 ... Through hole, 90, 91 ... Solder, 110, 111 ... Ground pattern , Q1, Q2, Q3, Q4, Q5, Q6, Q7 ... Switching transistors.

Claims (5)

A power converter equipped with a switching element
The base member on which the shielding wall is erected and
A cover member that closes the opening of the base member and
A circuit board arranged between the end of the shielding wall and the cover member,
With
The circuit board is a power conversion device having a plurality of through holes along the shielding wall. The power conversion device according to claim 1, wherein the through hole is connected to a ground pattern of a circuit board. The power conversion device according to claim 1 or 2, wherein solder is formed on at least one of the base member side and the cover member side corresponding to the shielding wall of the circuit board. The power conversion device according to claim 3, wherein the solder is in contact with an end portion of the shielding wall or the cover member. The power conversion device according to claim 3 or 4, wherein the solder is connected to a ground pattern of a circuit board.

Images